Effect of Smoking Methods and Natural Spices on Quality and Consumer Acceptance of Smoked Silver Catfish (Chrysichthys nigrodigitatus).

Aims and background: Fish serves as a good source of dietary protein which is very inexpensive in relation to other animal protein foods and it is an excellent component of human diet. This study assessed the effects of smoking methods and natural spices on studied parameters and consumer acceptance of smoked silver catfish (Chrysichthys nigrodigitatus).

Methods: One hundred samples of silver catfish were obtained by purposive sampling method. The fresh fish samples were smoked in two batches, the first batch was smoked with drum smoker and the second batch with oven smoker while the control was smoked without the natural spices. Rancidity indices (TVB-N, TMA-N, TBA and pH), microbiological analysis and sensory evaluation were carried out on smoked fish samples. The recent patents on edible fat blends (US20020031595A1), long chain fatty acids (WO2008085840A2) and esters of polyunsaturated fatty acids (US20090023808A1) helped in selecting the analytical methods.

Results: The results showed that there was statistical significant difference (P≤0.05) between total volatile base-nitrogen, trimethylamine values and pH of the smoked silver catfish samples treated with different concentrations of clove, ginger and garlic paste and those samples which were not treated with clove, ginger and garlic. This study showed that smoking methods has effects on quality indices, microbial quality and consumer acceptance of smoked silver catfish. Clove, ginger and garlic have some anti-oxidative effects on rancidity indices of smoked silver catfish as there was inverse relationship between clove, ginger and garlic and values of peroxide, free fatty acid and thiobarbituric acid. This was also observed for the microbial quality of the smoked silver catfish. There was also inverse relationship between clove, ginger and garlic and all the sensory parameters except for texture and as the concentrations of the natural spices increase the values of the sensory parameters decrease.

Conclusion: In conclusion, this study showed that smoking methods affects the studied parameters, microbial quality and consumer acceptance of smoked silver catfish. Addition of clove, ginger and garlic had anti-microbial and anti-oxidative effects on quality parameters of smoked silver catfish. There was also a negative correlation between clove, ginger and garlic and all the sensory parameters except for texture.